syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.0/5325 is trying to acquire lock:
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_try_to_free_truncate_log+0xb4/0x360 fs/ocfs2/alloc.c:6132

but task is already holding lock:
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_defrag_extent fs/ocfs2/move_extents.c:253 [inline]
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_move_extents+0x14f9/0x3aa0 fs/ocfs2/move_extents.c:937

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);
  lock(&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz.0.0/5325:
 #0: ffff888011fcc420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:543
 #1: ffff8880129d89c0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #1: ffff8880129d89c0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: ocfs2_move_extents+0x1f3/0x3aa0 fs/ocfs2/move_extents.c:915
 #2: ffff8880129d8660 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_move_extents+0x3cb/0x3aa0 fs/ocfs2/move_extents.c:935
 #3: ffff88801fcd9800 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #3: ffff88801fcd9800 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x16f/0x4790 fs/ocfs2/suballoc.c:789
 #4: ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #4: ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_defrag_extent fs/ocfs2/move_extents.c:253 [inline]
 #4: ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
 #4: ffff88801fcdd100 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_move_extents+0x14f9/0x3aa0 fs/ocfs2/move_extents.c:937

stack backtrace:
CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain kernel/locking/lockdep.c:3895 [inline]
 __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 down_write+0x96/0x200 kernel/locking/rwsem.c:1590
 inode_lock include/linux/fs.h:1027 [inline]
 ocfs2_try_to_free_truncate_log+0xb4/0x360 fs/ocfs2/alloc.c:6132
 ocfs2_reserve_clusters_with_limit+0x48d/0xc20 fs/ocfs2/suballoc.c:1187
 ocfs2_defrag_extent fs/ocfs2/move_extents.c:272 [inline]
 __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
 ocfs2_move_extents+0x186d/0x3aa0 fs/ocfs2/move_extents.c:937
 ocfs2_ioctl_move_extents+0x5bb/0x760 fs/ocfs2/move_extents.c:1069
 ocfs2_ioctl+0x195/0x7e0 fs/ocfs2/ioctl.c:942
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb9ddf9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb9def21028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb9de216090 RCX: 00007fb9ddf9aeb9
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000008
RBP: 00007fb9de008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb9de216128 R14: 00007fb9de216090 R15: 00007ffc1afbebb8
 </TASK>